TIME REQUIRED FOR INCUBATION 32] 



Time Required for Incubation. 



Under normal conditions of temper- 

 ature and other factors, it will take 

 the average hen's egg twenty-one 

 days to complete the process of in- 

 cubation, beginning from the time o I 

 the egg is subjected to 103 degrees, ^xU^ 3 ^Xlx*"^ 

 until the chick is entirely out of the 

 shell. Under artificial conditions, 

 there are causes which may vary the 

 hatching time twenty-four hours ^XjS^ X \^X' X 

 either way from the normal. In arti- 

 ficial incubation, the variation in xD ^ \ <&,> 

 temperature will materially decrease ^*^ 6 ^^\^ 

 or lengthen the hatching period. A I o o I 

 high temperature continued for a ^4x x ^ V ^xlx^ 

 number of days will shorten the 

 period, while a cool temperature ex- 

 tending over a considerable time will 

 often materially lengthen the hatch- xP \^ ^*^\s' 

 ing period to as many as twenty- 

 three days. It is an interesting fact vO I o^ >. ^ 

 that a variation of two or three ^J*^ 10 ^xJx^ 

 degrees from the normal temperature I 

 either way, providing the average ^^L/ n 

 temperature is normal, does not no- I 

 ticeably affect the hatch in any way. ^S^J^^ 12 



Varying amounts of moisture in 

 the incubator also materially affect V Q I/ s *9 9^ 



the time of hatching. A high humid- 

 ity during the last week, and espe- o 

 cially during the nineteenth and ^^l^ 14 

 twentieth days, will postpone the 

 hatch as much as from twelve to 

 twenty-four hours, but will usually 

 result in a quick, uniform, high per- 

 centage hatch. When managing the ^l^ 16 



incubator, long periods Of COoling FIG. 152. Manner of toe punching 



will increase the hatching period. biLJ^S&1t^2l 



Under natural methods, the eggS sixteen different matings. 



will hatch on the twenty-first day. 

 21 



